TRANSMAR: Europe-Asia 50 km Floating Bypass Viaduct, Istanbul, Turkey

A vital new connection

Istanbul, a great city enhanced by historical treasures and natural gifts and a settlement of 3,000,000 people few years ago, has lately been drawn under the unplanned influx of 10,000,000 more settlers immigrating from rural areas. Today, 70% of the city's building stock, mostly in the form of squatter housing, is without buiding and/or occupancy permits. Problems such as air, noise and light pollution, security weaknesses, ethnic clashes, loss of historical, cultural and natural entities and congested traffic are common in Istanbul.

The dense circulation today has become the nightmare of the people and the city's economics. Each day 600 cars obtain new license plate and join the traffic. It takes around 3 hours to travel from one to the other side of the city. The congested circulation constitutes potential danger in case of a serious earthquake.

In order to cope with the traffic problem, in 1973 the Government built a suspension bridge over the Bosphorus, the Straits bordering Europe and Asia. Yet, soon after the Bridge and its highways have become congested. The 2nd Bridge, intended to establish a speedway for transit and peripheral traffic was erected further north in 1988 and has been connected at both ends to TEM (Trans European Motorway). It has become congested, too in a short time. On the other hand, the construction of the 2nd Bridge and TEM have accelerated the northwardsly rapid, yet unplanned, urban growth transforming 250,000,000 sq m of green areas into ugly, mostly illegal concrete structures.

Today, both bridges planned for 250,000 cars per day in total carry 550,000 cars per day. And confused with such problems, the government proposes a 3rd Bridge over Bosphorus even further the north towards the Black Sea. Yet, since northern lands of the Bosphorus house the remaining green zones and water sources of the city, we believe building a third belt on the north will repeat the same cycle experienced with the 2nd Bridge and eventually turn the city towards the desertification trend, endangering the remaining 500,000,000 sq m forest zones of the Metropole.

TRANSMAR has born from this point. Since the north of Bosphorus is not suitable for a new highway system due to natural entities, and since south of Bosphorus is also not suitable for a new bridge due to its dense urbanisation and historical, cultural and natural treasures, the only reasonable solution was to go more south on the Sea of Marmara and built a bypass floating rail-road viaduct linking Europe to Asia across the water.

TRANSMAR begins on the European side from the Olympic Village, intersects the TEM, passes by the Ecological Village Project by architect Dr. Ken Yeang, goes under the Ataturk International Airport, leaves the European shore as a 9 km viaduct on pilotis at 25 m above sea level ,continues as a6 km floating viaduct. The 2 km double span cable-stayed fixed bridge at 65 m altitude allows large sea traffic. It is followed by a 14 km segment as a floating viaduct. The system sits on land on the Kinali Island which serves as a service and emergency center. The system leaves Kinali again with a 14 km floating viaduct segment and approaches the Asian shore with a 6 km viaduct on pilotis. It enters the Asian coast near the urban project by architect Zaha Hadid in Kartal, reaches the International Sabiha Gokcen Airport, reintersects with the TEM, and finally terminates at Istanbul Formula-1 Park.

It is expected that daily 100,000 vehicles will use TRANSMAR at a max speed of 100 km/h. The rail shuttle within the structure runs at 200 km/h and links the two Airports of the City in 15 mnts. The project's cost is estimated about 5 Blln USD and the payback period 15 years.